hw/acpi: add support for i440fx 'snooping' root busses
[qemu/kevin.git] / migration / block.c
blobddb59ccf877ba6d383fbf323d0e6eb19f4a29472
1 /*
2 * QEMU live block migration
4 * Copyright IBM, Corp. 2009
6 * Authors:
7 * Liran Schour <lirans@il.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
12 * Contributions after 2012-01-13 are licensed under the terms of the
13 * GNU GPL, version 2 or (at your option) any later version.
16 #include "qemu-common.h"
17 #include "block/block.h"
18 #include "qemu/error-report.h"
19 #include "qemu/main-loop.h"
20 #include "hw/hw.h"
21 #include "qemu/queue.h"
22 #include "qemu/timer.h"
23 #include "migration/block.h"
24 #include "migration/migration.h"
25 #include "sysemu/blockdev.h"
26 #include "sysemu/block-backend.h"
27 #include <assert.h>
29 #define BLOCK_SIZE (1 << 20)
30 #define BDRV_SECTORS_PER_DIRTY_CHUNK (BLOCK_SIZE >> BDRV_SECTOR_BITS)
32 #define BLK_MIG_FLAG_DEVICE_BLOCK 0x01
33 #define BLK_MIG_FLAG_EOS 0x02
34 #define BLK_MIG_FLAG_PROGRESS 0x04
35 #define BLK_MIG_FLAG_ZERO_BLOCK 0x08
37 #define MAX_IS_ALLOCATED_SEARCH 65536
39 //#define DEBUG_BLK_MIGRATION
41 #ifdef DEBUG_BLK_MIGRATION
42 #define DPRINTF(fmt, ...) \
43 do { printf("blk_migration: " fmt, ## __VA_ARGS__); } while (0)
44 #else
45 #define DPRINTF(fmt, ...) \
46 do { } while (0)
47 #endif
49 typedef struct BlkMigDevState {
50 /* Written during setup phase. Can be read without a lock. */
51 BlockDriverState *bs;
52 int shared_base;
53 int64_t total_sectors;
54 QSIMPLEQ_ENTRY(BlkMigDevState) entry;
56 /* Only used by migration thread. Does not need a lock. */
57 int bulk_completed;
58 int64_t cur_sector;
59 int64_t cur_dirty;
61 /* Protected by block migration lock. */
62 unsigned long *aio_bitmap;
63 int64_t completed_sectors;
64 BdrvDirtyBitmap *dirty_bitmap;
65 Error *blocker;
66 } BlkMigDevState;
68 typedef struct BlkMigBlock {
69 /* Only used by migration thread. */
70 uint8_t *buf;
71 BlkMigDevState *bmds;
72 int64_t sector;
73 int nr_sectors;
74 struct iovec iov;
75 QEMUIOVector qiov;
76 BlockAIOCB *aiocb;
78 /* Protected by block migration lock. */
79 int ret;
80 QSIMPLEQ_ENTRY(BlkMigBlock) entry;
81 } BlkMigBlock;
83 typedef struct BlkMigState {
84 /* Written during setup phase. Can be read without a lock. */
85 int blk_enable;
86 int shared_base;
87 QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list;
88 int64_t total_sector_sum;
89 bool zero_blocks;
91 /* Protected by lock. */
92 QSIMPLEQ_HEAD(blk_list, BlkMigBlock) blk_list;
93 int submitted;
94 int read_done;
96 /* Only used by migration thread. Does not need a lock. */
97 int transferred;
98 int prev_progress;
99 int bulk_completed;
101 /* Lock must be taken _inside_ the iothread lock. */
102 QemuMutex lock;
103 } BlkMigState;
105 static BlkMigState block_mig_state;
107 static void blk_mig_lock(void)
109 qemu_mutex_lock(&block_mig_state.lock);
112 static void blk_mig_unlock(void)
114 qemu_mutex_unlock(&block_mig_state.lock);
117 /* Must run outside of the iothread lock during the bulk phase,
118 * or the VM will stall.
121 static void blk_send(QEMUFile *f, BlkMigBlock * blk)
123 int len;
124 uint64_t flags = BLK_MIG_FLAG_DEVICE_BLOCK;
126 if (block_mig_state.zero_blocks &&
127 buffer_is_zero(blk->buf, BLOCK_SIZE)) {
128 flags |= BLK_MIG_FLAG_ZERO_BLOCK;
131 /* sector number and flags */
132 qemu_put_be64(f, (blk->sector << BDRV_SECTOR_BITS)
133 | flags);
135 /* device name */
136 len = strlen(bdrv_get_device_name(blk->bmds->bs));
137 qemu_put_byte(f, len);
138 qemu_put_buffer(f, (uint8_t *)bdrv_get_device_name(blk->bmds->bs), len);
140 /* if a block is zero we need to flush here since the network
141 * bandwidth is now a lot higher than the storage device bandwidth.
142 * thus if we queue zero blocks we slow down the migration */
143 if (flags & BLK_MIG_FLAG_ZERO_BLOCK) {
144 qemu_fflush(f);
145 return;
148 qemu_put_buffer(f, blk->buf, BLOCK_SIZE);
151 int blk_mig_active(void)
153 return !QSIMPLEQ_EMPTY(&block_mig_state.bmds_list);
156 uint64_t blk_mig_bytes_transferred(void)
158 BlkMigDevState *bmds;
159 uint64_t sum = 0;
161 blk_mig_lock();
162 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
163 sum += bmds->completed_sectors;
165 blk_mig_unlock();
166 return sum << BDRV_SECTOR_BITS;
169 uint64_t blk_mig_bytes_remaining(void)
171 return blk_mig_bytes_total() - blk_mig_bytes_transferred();
174 uint64_t blk_mig_bytes_total(void)
176 BlkMigDevState *bmds;
177 uint64_t sum = 0;
179 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
180 sum += bmds->total_sectors;
182 return sum << BDRV_SECTOR_BITS;
186 /* Called with migration lock held. */
188 static int bmds_aio_inflight(BlkMigDevState *bmds, int64_t sector)
190 int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
192 if (sector < bdrv_nb_sectors(bmds->bs)) {
193 return !!(bmds->aio_bitmap[chunk / (sizeof(unsigned long) * 8)] &
194 (1UL << (chunk % (sizeof(unsigned long) * 8))));
195 } else {
196 return 0;
200 /* Called with migration lock held. */
202 static void bmds_set_aio_inflight(BlkMigDevState *bmds, int64_t sector_num,
203 int nb_sectors, int set)
205 int64_t start, end;
206 unsigned long val, idx, bit;
208 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
209 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
211 for (; start <= end; start++) {
212 idx = start / (sizeof(unsigned long) * 8);
213 bit = start % (sizeof(unsigned long) * 8);
214 val = bmds->aio_bitmap[idx];
215 if (set) {
216 val |= 1UL << bit;
217 } else {
218 val &= ~(1UL << bit);
220 bmds->aio_bitmap[idx] = val;
224 static void alloc_aio_bitmap(BlkMigDevState *bmds)
226 BlockDriverState *bs = bmds->bs;
227 int64_t bitmap_size;
229 bitmap_size = bdrv_nb_sectors(bs) + BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
230 bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
232 bmds->aio_bitmap = g_malloc0(bitmap_size);
235 /* Never hold migration lock when yielding to the main loop! */
237 static void blk_mig_read_cb(void *opaque, int ret)
239 BlkMigBlock *blk = opaque;
241 blk_mig_lock();
242 blk->ret = ret;
244 QSIMPLEQ_INSERT_TAIL(&block_mig_state.blk_list, blk, entry);
245 bmds_set_aio_inflight(blk->bmds, blk->sector, blk->nr_sectors, 0);
247 block_mig_state.submitted--;
248 block_mig_state.read_done++;
249 assert(block_mig_state.submitted >= 0);
250 blk_mig_unlock();
253 /* Called with no lock taken. */
255 static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
257 int64_t total_sectors = bmds->total_sectors;
258 int64_t cur_sector = bmds->cur_sector;
259 BlockDriverState *bs = bmds->bs;
260 BlkMigBlock *blk;
261 int nr_sectors;
263 if (bmds->shared_base) {
264 qemu_mutex_lock_iothread();
265 while (cur_sector < total_sectors &&
266 !bdrv_is_allocated(bs, cur_sector, MAX_IS_ALLOCATED_SEARCH,
267 &nr_sectors)) {
268 cur_sector += nr_sectors;
270 qemu_mutex_unlock_iothread();
273 if (cur_sector >= total_sectors) {
274 bmds->cur_sector = bmds->completed_sectors = total_sectors;
275 return 1;
278 bmds->completed_sectors = cur_sector;
280 cur_sector &= ~((int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK - 1);
282 /* we are going to transfer a full block even if it is not allocated */
283 nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
285 if (total_sectors - cur_sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
286 nr_sectors = total_sectors - cur_sector;
289 blk = g_new(BlkMigBlock, 1);
290 blk->buf = g_malloc(BLOCK_SIZE);
291 blk->bmds = bmds;
292 blk->sector = cur_sector;
293 blk->nr_sectors = nr_sectors;
295 blk->iov.iov_base = blk->buf;
296 blk->iov.iov_len = nr_sectors * BDRV_SECTOR_SIZE;
297 qemu_iovec_init_external(&blk->qiov, &blk->iov, 1);
299 blk_mig_lock();
300 block_mig_state.submitted++;
301 blk_mig_unlock();
303 qemu_mutex_lock_iothread();
304 blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov,
305 nr_sectors, blk_mig_read_cb, blk);
307 bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, cur_sector, nr_sectors);
308 qemu_mutex_unlock_iothread();
310 bmds->cur_sector = cur_sector + nr_sectors;
311 return (bmds->cur_sector >= total_sectors);
314 /* Called with iothread lock taken. */
316 static int set_dirty_tracking(void)
318 BlkMigDevState *bmds;
319 int ret;
321 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
322 bmds->dirty_bitmap = bdrv_create_dirty_bitmap(bmds->bs, BLOCK_SIZE,
323 NULL, NULL);
324 if (!bmds->dirty_bitmap) {
325 ret = -errno;
326 goto fail;
329 return 0;
331 fail:
332 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
333 if (bmds->dirty_bitmap) {
334 bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
337 return ret;
340 static void unset_dirty_tracking(void)
342 BlkMigDevState *bmds;
344 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
345 bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
349 static void init_blk_migration(QEMUFile *f)
351 BlockDriverState *bs;
352 BlkMigDevState *bmds;
353 int64_t sectors;
355 block_mig_state.submitted = 0;
356 block_mig_state.read_done = 0;
357 block_mig_state.transferred = 0;
358 block_mig_state.total_sector_sum = 0;
359 block_mig_state.prev_progress = -1;
360 block_mig_state.bulk_completed = 0;
361 block_mig_state.zero_blocks = migrate_zero_blocks();
363 for (bs = bdrv_next(NULL); bs; bs = bdrv_next(bs)) {
364 if (bdrv_is_read_only(bs)) {
365 continue;
368 sectors = bdrv_nb_sectors(bs);
369 if (sectors <= 0) {
370 return;
373 bmds = g_new0(BlkMigDevState, 1);
374 bmds->bs = bs;
375 bmds->bulk_completed = 0;
376 bmds->total_sectors = sectors;
377 bmds->completed_sectors = 0;
378 bmds->shared_base = block_mig_state.shared_base;
379 alloc_aio_bitmap(bmds);
380 error_setg(&bmds->blocker, "block device is in use by migration");
381 bdrv_op_block_all(bs, bmds->blocker);
382 bdrv_ref(bs);
384 block_mig_state.total_sector_sum += sectors;
386 if (bmds->shared_base) {
387 DPRINTF("Start migration for %s with shared base image\n",
388 bdrv_get_device_name(bs));
389 } else {
390 DPRINTF("Start full migration for %s\n", bdrv_get_device_name(bs));
393 QSIMPLEQ_INSERT_TAIL(&block_mig_state.bmds_list, bmds, entry);
397 /* Called with no lock taken. */
399 static int blk_mig_save_bulked_block(QEMUFile *f)
401 int64_t completed_sector_sum = 0;
402 BlkMigDevState *bmds;
403 int progress;
404 int ret = 0;
406 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
407 if (bmds->bulk_completed == 0) {
408 if (mig_save_device_bulk(f, bmds) == 1) {
409 /* completed bulk section for this device */
410 bmds->bulk_completed = 1;
412 completed_sector_sum += bmds->completed_sectors;
413 ret = 1;
414 break;
415 } else {
416 completed_sector_sum += bmds->completed_sectors;
420 if (block_mig_state.total_sector_sum != 0) {
421 progress = completed_sector_sum * 100 /
422 block_mig_state.total_sector_sum;
423 } else {
424 progress = 100;
426 if (progress != block_mig_state.prev_progress) {
427 block_mig_state.prev_progress = progress;
428 qemu_put_be64(f, (progress << BDRV_SECTOR_BITS)
429 | BLK_MIG_FLAG_PROGRESS);
430 DPRINTF("Completed %d %%\r", progress);
433 return ret;
436 static void blk_mig_reset_dirty_cursor(void)
438 BlkMigDevState *bmds;
440 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
441 bmds->cur_dirty = 0;
445 /* Called with iothread lock taken. */
447 static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds,
448 int is_async)
450 BlkMigBlock *blk;
451 int64_t total_sectors = bmds->total_sectors;
452 int64_t sector;
453 int nr_sectors;
454 int ret = -EIO;
456 for (sector = bmds->cur_dirty; sector < bmds->total_sectors;) {
457 blk_mig_lock();
458 if (bmds_aio_inflight(bmds, sector)) {
459 blk_mig_unlock();
460 bdrv_drain_all();
461 } else {
462 blk_mig_unlock();
464 if (bdrv_get_dirty(bmds->bs, bmds->dirty_bitmap, sector)) {
466 if (total_sectors - sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
467 nr_sectors = total_sectors - sector;
468 } else {
469 nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
471 blk = g_new(BlkMigBlock, 1);
472 blk->buf = g_malloc(BLOCK_SIZE);
473 blk->bmds = bmds;
474 blk->sector = sector;
475 blk->nr_sectors = nr_sectors;
477 if (is_async) {
478 blk->iov.iov_base = blk->buf;
479 blk->iov.iov_len = nr_sectors * BDRV_SECTOR_SIZE;
480 qemu_iovec_init_external(&blk->qiov, &blk->iov, 1);
482 blk->aiocb = bdrv_aio_readv(bmds->bs, sector, &blk->qiov,
483 nr_sectors, blk_mig_read_cb, blk);
485 blk_mig_lock();
486 block_mig_state.submitted++;
487 bmds_set_aio_inflight(bmds, sector, nr_sectors, 1);
488 blk_mig_unlock();
489 } else {
490 ret = bdrv_read(bmds->bs, sector, blk->buf, nr_sectors);
491 if (ret < 0) {
492 goto error;
494 blk_send(f, blk);
496 g_free(blk->buf);
497 g_free(blk);
500 bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, sector, nr_sectors);
501 break;
503 sector += BDRV_SECTORS_PER_DIRTY_CHUNK;
504 bmds->cur_dirty = sector;
507 return (bmds->cur_dirty >= bmds->total_sectors);
509 error:
510 DPRINTF("Error reading sector %" PRId64 "\n", sector);
511 g_free(blk->buf);
512 g_free(blk);
513 return ret;
516 /* Called with iothread lock taken.
518 * return value:
519 * 0: too much data for max_downtime
520 * 1: few enough data for max_downtime
522 static int blk_mig_save_dirty_block(QEMUFile *f, int is_async)
524 BlkMigDevState *bmds;
525 int ret = 1;
527 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
528 ret = mig_save_device_dirty(f, bmds, is_async);
529 if (ret <= 0) {
530 break;
534 return ret;
537 /* Called with no locks taken. */
539 static int flush_blks(QEMUFile *f)
541 BlkMigBlock *blk;
542 int ret = 0;
544 DPRINTF("%s Enter submitted %d read_done %d transferred %d\n",
545 __FUNCTION__, block_mig_state.submitted, block_mig_state.read_done,
546 block_mig_state.transferred);
548 blk_mig_lock();
549 while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
550 if (qemu_file_rate_limit(f)) {
551 break;
553 if (blk->ret < 0) {
554 ret = blk->ret;
555 break;
558 QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry);
559 blk_mig_unlock();
560 blk_send(f, blk);
561 blk_mig_lock();
563 g_free(blk->buf);
564 g_free(blk);
566 block_mig_state.read_done--;
567 block_mig_state.transferred++;
568 assert(block_mig_state.read_done >= 0);
570 blk_mig_unlock();
572 DPRINTF("%s Exit submitted %d read_done %d transferred %d\n", __FUNCTION__,
573 block_mig_state.submitted, block_mig_state.read_done,
574 block_mig_state.transferred);
575 return ret;
578 /* Called with iothread lock taken. */
580 static int64_t get_remaining_dirty(void)
582 BlkMigDevState *bmds;
583 int64_t dirty = 0;
585 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
586 dirty += bdrv_get_dirty_count(bmds->dirty_bitmap);
589 return dirty << BDRV_SECTOR_BITS;
592 /* Called with iothread lock taken. */
594 static void blk_mig_cleanup(void)
596 BlkMigDevState *bmds;
597 BlkMigBlock *blk;
599 bdrv_drain_all();
601 unset_dirty_tracking();
603 blk_mig_lock();
604 while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) {
605 QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry);
606 bdrv_op_unblock_all(bmds->bs, bmds->blocker);
607 error_free(bmds->blocker);
608 bdrv_unref(bmds->bs);
609 g_free(bmds->aio_bitmap);
610 g_free(bmds);
613 while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
614 QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry);
615 g_free(blk->buf);
616 g_free(blk);
618 blk_mig_unlock();
621 static void block_migration_cancel(void *opaque)
623 blk_mig_cleanup();
626 static int block_save_setup(QEMUFile *f, void *opaque)
628 int ret;
630 DPRINTF("Enter save live setup submitted %d transferred %d\n",
631 block_mig_state.submitted, block_mig_state.transferred);
633 qemu_mutex_lock_iothread();
634 init_blk_migration(f);
636 /* start track dirty blocks */
637 ret = set_dirty_tracking();
639 if (ret) {
640 qemu_mutex_unlock_iothread();
641 return ret;
644 qemu_mutex_unlock_iothread();
646 ret = flush_blks(f);
647 blk_mig_reset_dirty_cursor();
648 qemu_put_be64(f, BLK_MIG_FLAG_EOS);
650 return ret;
653 static int block_save_iterate(QEMUFile *f, void *opaque)
655 int ret;
656 int64_t last_ftell = qemu_ftell(f);
657 int64_t delta_ftell;
659 DPRINTF("Enter save live iterate submitted %d transferred %d\n",
660 block_mig_state.submitted, block_mig_state.transferred);
662 ret = flush_blks(f);
663 if (ret) {
664 return ret;
667 blk_mig_reset_dirty_cursor();
669 /* control the rate of transfer */
670 blk_mig_lock();
671 while ((block_mig_state.submitted +
672 block_mig_state.read_done) * BLOCK_SIZE <
673 qemu_file_get_rate_limit(f)) {
674 blk_mig_unlock();
675 if (block_mig_state.bulk_completed == 0) {
676 /* first finish the bulk phase */
677 if (blk_mig_save_bulked_block(f) == 0) {
678 /* finished saving bulk on all devices */
679 block_mig_state.bulk_completed = 1;
681 ret = 0;
682 } else {
683 /* Always called with iothread lock taken for
684 * simplicity, block_save_complete also calls it.
686 qemu_mutex_lock_iothread();
687 ret = blk_mig_save_dirty_block(f, 1);
688 qemu_mutex_unlock_iothread();
690 if (ret < 0) {
691 return ret;
693 blk_mig_lock();
694 if (ret != 0) {
695 /* no more dirty blocks */
696 break;
699 blk_mig_unlock();
701 ret = flush_blks(f);
702 if (ret) {
703 return ret;
706 qemu_put_be64(f, BLK_MIG_FLAG_EOS);
707 delta_ftell = qemu_ftell(f) - last_ftell;
708 if (delta_ftell > 0) {
709 return 1;
710 } else if (delta_ftell < 0) {
711 return -1;
712 } else {
713 return 0;
717 /* Called with iothread lock taken. */
719 static int block_save_complete(QEMUFile *f, void *opaque)
721 int ret;
723 DPRINTF("Enter save live complete submitted %d transferred %d\n",
724 block_mig_state.submitted, block_mig_state.transferred);
726 ret = flush_blks(f);
727 if (ret) {
728 return ret;
731 blk_mig_reset_dirty_cursor();
733 /* we know for sure that save bulk is completed and
734 all async read completed */
735 blk_mig_lock();
736 assert(block_mig_state.submitted == 0);
737 blk_mig_unlock();
739 do {
740 ret = blk_mig_save_dirty_block(f, 0);
741 if (ret < 0) {
742 return ret;
744 } while (ret == 0);
746 /* report completion */
747 qemu_put_be64(f, (100 << BDRV_SECTOR_BITS) | BLK_MIG_FLAG_PROGRESS);
749 DPRINTF("Block migration completed\n");
751 qemu_put_be64(f, BLK_MIG_FLAG_EOS);
753 blk_mig_cleanup();
754 return 0;
757 static uint64_t block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
759 /* Estimate pending number of bytes to send */
760 uint64_t pending;
762 qemu_mutex_lock_iothread();
763 blk_mig_lock();
764 pending = get_remaining_dirty() +
765 block_mig_state.submitted * BLOCK_SIZE +
766 block_mig_state.read_done * BLOCK_SIZE;
768 /* Report at least one block pending during bulk phase */
769 if (pending <= max_size && !block_mig_state.bulk_completed) {
770 pending = max_size + BLOCK_SIZE;
772 blk_mig_unlock();
773 qemu_mutex_unlock_iothread();
775 DPRINTF("Enter save live pending %" PRIu64 "\n", pending);
776 return pending;
779 static int block_load(QEMUFile *f, void *opaque, int version_id)
781 static int banner_printed;
782 int len, flags;
783 char device_name[256];
784 int64_t addr;
785 BlockDriverState *bs, *bs_prev = NULL;
786 BlockBackend *blk;
787 uint8_t *buf;
788 int64_t total_sectors = 0;
789 int nr_sectors;
790 int ret;
792 do {
793 addr = qemu_get_be64(f);
795 flags = addr & ~BDRV_SECTOR_MASK;
796 addr >>= BDRV_SECTOR_BITS;
798 if (flags & BLK_MIG_FLAG_DEVICE_BLOCK) {
799 /* get device name */
800 len = qemu_get_byte(f);
801 qemu_get_buffer(f, (uint8_t *)device_name, len);
802 device_name[len] = '\0';
804 blk = blk_by_name(device_name);
805 if (!blk) {
806 fprintf(stderr, "Error unknown block device %s\n",
807 device_name);
808 return -EINVAL;
810 bs = blk_bs(blk);
812 if (bs != bs_prev) {
813 bs_prev = bs;
814 total_sectors = bdrv_nb_sectors(bs);
815 if (total_sectors <= 0) {
816 error_report("Error getting length of block device %s",
817 device_name);
818 return -EINVAL;
822 if (total_sectors - addr < BDRV_SECTORS_PER_DIRTY_CHUNK) {
823 nr_sectors = total_sectors - addr;
824 } else {
825 nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
828 if (flags & BLK_MIG_FLAG_ZERO_BLOCK) {
829 ret = bdrv_write_zeroes(bs, addr, nr_sectors,
830 BDRV_REQ_MAY_UNMAP);
831 } else {
832 buf = g_malloc(BLOCK_SIZE);
833 qemu_get_buffer(f, buf, BLOCK_SIZE);
834 ret = bdrv_write(bs, addr, buf, nr_sectors);
835 g_free(buf);
838 if (ret < 0) {
839 return ret;
841 } else if (flags & BLK_MIG_FLAG_PROGRESS) {
842 if (!banner_printed) {
843 printf("Receiving block device images\n");
844 banner_printed = 1;
846 printf("Completed %d %%%c", (int)addr,
847 (addr == 100) ? '\n' : '\r');
848 fflush(stdout);
849 } else if (!(flags & BLK_MIG_FLAG_EOS)) {
850 fprintf(stderr, "Unknown block migration flags: %#x\n", flags);
851 return -EINVAL;
853 ret = qemu_file_get_error(f);
854 if (ret != 0) {
855 return ret;
857 } while (!(flags & BLK_MIG_FLAG_EOS));
859 return 0;
862 static void block_set_params(const MigrationParams *params, void *opaque)
864 block_mig_state.blk_enable = params->blk;
865 block_mig_state.shared_base = params->shared;
867 /* shared base means that blk_enable = 1 */
868 block_mig_state.blk_enable |= params->shared;
871 static bool block_is_active(void *opaque)
873 return block_mig_state.blk_enable == 1;
876 static SaveVMHandlers savevm_block_handlers = {
877 .set_params = block_set_params,
878 .save_live_setup = block_save_setup,
879 .save_live_iterate = block_save_iterate,
880 .save_live_complete = block_save_complete,
881 .save_live_pending = block_save_pending,
882 .load_state = block_load,
883 .cancel = block_migration_cancel,
884 .is_active = block_is_active,
887 void blk_mig_init(void)
889 QSIMPLEQ_INIT(&block_mig_state.bmds_list);
890 QSIMPLEQ_INIT(&block_mig_state.blk_list);
891 qemu_mutex_init(&block_mig_state.lock);
893 register_savevm_live(NULL, "block", 0, 1, &savevm_block_handlers,
894 &block_mig_state);